1. Field of the Invention
This invention relates generally to a safety system for a home heating system or hot-water heater and, more particularly, to such safety system using a smoke detector and the existing power interruption switch of the heating system.
2. Description of the Background
One of the common hazards associated with the burning of fuel for the heating of a home or the heating of water used in the home is that the smoke and combustion gasses resulting from such burning are not properly and safely vented to outside the home. This improper venting may be caused by many things, including the blocking of the chimney by animals or birds; the obstruction of the smoke passages within a heating system or boiler due to the accumulation of carbon and other combustion particles, which is especially true in newer, high-efficiency units with smaller passages; the disconnection of the heating system or boiler from the chimney due to the improper connection or repeated vibration of the connecting piping; and fire leaking from the boiler or heating system due to damage, or failure of the boiler or heating system.
There are many hazards associated with improperly vented smoke and combustion gasses, such as asphyxiation of the occupants of the structure by carbon monoxide and other combustion gasses, and the sooty accumulation of smoke within the house and on the contents. Also, if the smoke is the result of fire leakage, there is the chance that the leaking fire will eventually cause the structure to burn.
Almost all home heating systems, and many domestic water heaters, have a safety switch, usually located at the head of the basement stairway, so that the homeowner can interrupt the power to the heating system in case of an emergency. Typically, the homeowner or emergency worker smells smoke or notes some other malfunction and throws the switch, thereby interrupting the electrical supply to the heating system. This power interruption then shuts down the entire heating system, that is, in the case of a gas or oil-fired heating system the supply of fuel to the combustion element is ultimately interrupted and the heating system stops functioning.
Of course, the use of residential smoke detectors has become widespread and the benefits of these devices are well known. Typically, when using a smoke detector, the occupant hears and/or sees the alarm and, in the case of a heating system problem, turns off the heating system using the safety shut-off switch, as described above.
A system that can interrupt the power to an electric range and that employs a smoke or flame detector has previously been described in U.S. Pat. No. 4,659,909. This system is wired into the power connection to the electric range, which typically does not have a safety shut-off switch of the kind provided for a heating system.
These existing systems have all been found to have one or more drawbacks affecting their safety, performance, and convenience. For example, in the case of the conventional smoke alarm, the occupant must manually throw the safety switch. If a problem occurs when no one is home the safety system can, of course, not be activated. In the case of the electric range shut offs, a 120/210 volts power supply line is used to trip a circuit breaker switch.